State-to-state vibrational predissociation dynamics of the acetylene-HF complex

The vibrational predissociation of the acetylene-HF complex has been studied by probing the final state distributions of the photofragments, including the intermolecular scalar correlations. Results are presented for excitation of both the asymmetric C–H stretching vibration of the acetylene and the H–F stretch. In the latter case, the primary dissociation channel is V–R, resulting in highly rotationally excited HF produced in coincidence with ground vibrational state acetylene. Excitation of the asymmetric C–H stretch results in intramolecular V–V energy transfer to the C–C stretch excited state of the acetylene. The dissociation energy of the complex is determined to be 1088 cm−1±2 cm−1.